frontend engineer

Xin Liu

Frontend React Developer

Email: **********@*****.*** Phone: 201-***-****

https://www.linkedin.com/in/xin-liu-9ab8027b/

Professional Summary

Senior Frontend Engineer with 10+ years of experience building scalable, high-performance web applications and enterprise UI platforms.

Experts in React, TypeScript, Next.js, modern JavaScript, component architecture, and API integrations for enterprise clients in banking, telecom, retails, and e-commerce domains.

Proven track record improving performance, reducing delivery time, and creating reusable design systems, and Agile/Scrum collaboration.

Experienced in contract consulting and fast-paced enterprise environments, Strong collaborator with product, UX, backend, and QA teams.

Available for C2C / Corp to Corp Contract positions, Immediate joining.

Technical Skills

Frontend: React, React Native, Redux, TypeScript, Next.js, JavaScript (ES6+), HTML5, CSS3, Tailwind, Material-UI, Bootstrap

UI/UX: Responsive Design, Material-UI, Tailwind CSS, Mobile Web, Single Page Applications

Tools: Git, Jira, Webpack, Vite, Docker, VS Code, Babel, Storybook

Testing: Jest, React Testing Library, Cypress

Cloud: AWS (S3, EC2, Lambda), Azure, Docker, Jenkins, CI/CD

Backend: Node.js, Express, REST API, Java, Python, NodeJS, SQL, Spring boot, Maven, Oracle SQL, MySQL, MongoDB, PostgreSQL, Prisma

Other: Agile/Scrum, Accessibility (WCAG), Figma, Debugging & Performance Optimization

Professional Experience

Senior/Lead Frontend React Developer February 2025 – Present

Client – United Group, Harrisburg, NC Jago Link Inc

POS E-Commerce Agent Platform

POS company Agent Platform has highly interactive POS products pages with views, reviews, features, and dynamic recommendation sections, advanced search and filtering experience using debounced queries and server-side search integration, also has multi-step checkout flows with robust form validation, payment gateway integration, and error-handling logic.

Responsibilities:

Build and maintain reusable code and libraries for multiple frontend projects, optimize application for high performance and scalability and ensure the technical feasibility of UI/UX designs and user friendly.

Create operational overviews and write requirement analysis, mock-ups, test plans and documentation for new reports in Jira environment to cover gaps between initially delivered functionality and business requirements.

Work with React/Next tech stack, React Hooks, TypeScript, JavaScript, HTML, CSS, sass, react router, React Native, expo to implementation component, views, dashboard, web and iOS Android mobile application based on client requirements.

Work with PM, UX, QA from design to Wireframe, Prototype, UML, Figma, micro design system, client company components lib dependency, Tailwind CSS, responsive, flex display, Media Query, ShadCN, Material-UI, PNG, SVG, image loading, gather requirements, create technical design documents, and customize various components depending on main business lines.

Implement application state management and share state by createContext, Provider, useContext, useReducer, build complex enterprise state management by Redux, Redux Toolkit, Zustand, perform async action and side effect by redux-thunk, redux-saga, and manage server state by react-query based on application architect.

Use useCallback, memo, useMemo, useEffect, or latest react Complier to improve and optimize performance, use Rxjs for Observables pattern, pipe, and subscribe to compose asynchronous, event-based code, and session management.

Create react reusable component, custom Hooks, use useRef for necessary native DOM manipulation, third-party DOM JavaScript library integration, uncontrol form element, or use useState for control components, state update, and element rearrange.

Implement app silent/hot updates for new features and release version by useAutoUpdate Hooks to poll and refresh background version Json and reload the updates.

Integrate with REST APIs, use useTransaction for dynamic data async fetch and actions, create services layer and until functions to preprocess data structure for response or payload to perform Modal popup, form submission, and user interactions, work with java, backend, python to convert and pass data to frontend.

Utilize cloud technology and DevOps to config Node.js server and vercel, Git actions for CICD, set up and use copilot AI tools and agent in IDE for code efficiency.

Sr. Front-End React Developer June 2023 – Jan 2025

Client: Duke Energy, Charlotte, NC Dexian LLC

Google Map Redesign - Payment Locations, Nuclear Safety

https://www.duke-energy.com/home/billing/payment-locations

https://www.duke-energy.com/safety-and-preparedness/nuclear-safety/catawba-map

https://www.duke-energy.com/safety-and-preparedness/nuclear-safety/harris-map

Google map redesign uses the latest Google map API version to build react map components on Duke public web and mobile web for business needs and public awareness.

MAM - My Account Modernization

MAM is for customer accounts management, personalization, billing management, and payments, it uses React frontend and migrates from existing augular.js web. MAM has a new and Modern UX for UI and it uses next.js for production, Sitecore as content management, façade API, C#, and ASP.net as the backend.

Responsibilities:

Communicate with UX, PM, and QA to determine requirements, use Figma design tool for app and react component dev, implement custom clusters and markers by PNG or SVG from design, and create Restful API call to get Duke map Json data to render the markers.

Create and use useRef to link to google map clusters DOM ref for DOM manipulations such as add or remove markers on the map, attach native event listeners such as on hover, click, mouse enter or leave to update active marker style for user interaction.

Use electron UX design and micro wireframe to implement modernization UI in react Frontend for dashboard Billing and Payment programs, additional Offerings, and tailwind dynamic responsive class calculation and mapping.

Work on Step Views, multiple Modals, forms submit, and frontend logics on state management and calculations to serve UI functions and wrap the content management system such as Sitecore data to pass into the component as company standard reusable content data complement.

Involved in working on duke DXT web services and frontend cloud migration using AWS, IAM, EC2, and Lambda service.

Sr. Frontend React Developer April 2022 – May 2023

Client – Lowes, Charlotte, NC Jago Link Inc

MRV Returns UI

MRV Returns UI handles Lowes returns checkout flow and enables the store assistant to manually enter Invoice, receipt, item, and numbers, or scan the items, and it has UI static data features by DACI.

Responsibilities:

Solved difficult technical problems with flexible, scalable, maintainable, and extensible solution designs, conducted root cause analysis of issues, and reviews new and existing code.

Implemented global state management by combining using useReducer, createContext, Provider, useContext, and new react dev tools such as useReducer and useContext for debugging and troubleshooting, and used useCallback and useMemo to improve performance, and decomposed event listeners from loop element, used data-id and moved callback handler to upper layer element.

Applied Observable Design Pattern, added observable objects to grid source props, and notified observer for data updates and changes, used react-query for API call response data and state management.

Worked with design system Figma and involved in production and QA process and used scss to add nested rules, variables, and selector inheritance for component style.

Implemented UI Automation testing by cypress, cucumber, fixtures, steps definitions, used React Testing Library and Jest to create unit test case and improved code coverage by coverage, simulate user event by fireEvent, test React hooks by renderHook, and mock API calls in React component.

Worked with Jenkins for Continue Integration and GCP - Google Cloud Platform for Continue Deployment, configured Docker file and container gateway in the project to build the frontend docker image, exposed container port and deploy on GCP.

React UI Lead Developer February 2021 – March 2022

Client – AT&T, Plano, TX Jago Link Inc

Unlock UI

https://www.att.com/deviceunlock/

Support Common Widget

https://www.att.com/support/topic/u-verse-high-speed-internet/

Smart Home Manager

SHM is a new design application that provides Network connection dialog and speed test for AT&T Customers who use AT&T devices to manage their home devices with the AT&T users account and login.

Responsibilities:

Developed Accessibility features depending on WCAG compliance and web accessibility requirements and standards, used ANDI tool to debug Accessibility defects, fixed Support Common Widget CATO Accessibility production defects.

Analyzed, troubleshot, and architect solutions to solve defects, challenges, incidents, and production issues.

Integrated Login component for Smart Home Manager, provided route and redirect back to network landing page by browser history, enforced user login by checking browser cookies, investigated long polling react to consume dynamic data and server connection.

Configured API call request headers, Authorization, security-token, request Id, tested services in postman, and implemented API call by fetch, and async await.

Optimized Performance and code quality, refactored, improved coding structure for scalability, and reduced page loading time for high performance.

Worked with SSR - Servers Side Rendering framework Next.js and used app shell for local react CSR - Clients Side Rendering, consumed CMS Content Management System - AEM Adobe Content Management data by CMS feed API call, passed and filtered by page name property to divide CMS Json for each page component and the UI.

Worked with CICD tools, Jenkins, and AT&T ECO deployment pipeline, fixed failed build, troubleshoot and debug frontend side, released new features and functionalities to production.

Full-Stack Developer July 2019 – January 2021

Client – Ameriprise Financial Inc, Minneapolis, MN Jago Link Inc

Business Alliance Process Improvement

eSignature uses react frontend and has rich reusable, libs functions, data dependencies from homepage, and frontend components, it serves as a platform for holding applications and integrations with forms and business workflow, linking application by context and routing to eSign so the advisors and clients can perform eSignature for different WIP – work in process applications.

Signing packets use react frontend and provide a signature pad for advisors, clients, or non-client to sign PDF in WIPs that routes from eForms manager, and the applications integrated in the eSignature platform for multiple signer documents eSignatures.

eSignature services run backend application services that provide signed pdf documents business, which uses CRE – central rule engine for pre-process user relationship checking for form submission.

Responsibilities:

Created API in controllers and services to consume upstream internal services, used Java and Spring boot microservices to implement CRE – Centralized Rule Engine services by rulebook, debugged signed Documents and tested rules services.

Enhanced eForms Manager and eSignature platform applications based on new business requirements from BA team for line of business to create functional design documents and customize various modules.

Created React components using JSX, used Redux Architecture for data flow and managed data in React state and redux reducer, used redux-thunk dispatch, redux-saga for asynchronous actions for API calls, and fetch services AJAX call by axios.

Used Postman to check Java Spring Boot microservices and the response and JSON for frontend development.

Implemented Stand-alone React components, reusable functions and developed responsive design website that could be served to desktop, Tablets, and mobile users, and used Material UI to create atom components and developed the web application with the newest React features, typescript, and centralized react state with Hooks.

Frontend React Developer Feb 2018 – June 2019

Client: Wells Fargo, Charlotte, NC Anagh Tech Inc

CBUW (Credit Bridge Under Writing)

CBUW simulates the process for creating new credit applications in actual business with its simulator migrating from the existing scheme to current CBUW scheme.

CBBSRI (Credit Bridge Business Service – Rule Integration)

CBBSRI serves the Business Service operated by Wells Fargo, moves the services online, and facilitates the managers to review, modify, approve, withdraw, deactivate, update, or save the Business Rules. It includes Dashboard Module and functionalities such as rule popup modal depending on business requirements.

CBDAO (Credit Bridge Deal Approval & Onboarding)

CBDAO serves the Credit Product line of business in Wells Fargo, including Current/Proposed Exposure, Deal Tracking, Approval, Product Application, Product Detail, related Party, Borrower and so on.

Responsibilities:

Designed and developed the Exposure page and module, from the entrance in Portfolio landing page to Exposure, implemented functionalities depending on business requirements and Tab View for switching between the Current and Proposed Exposure.

Implemented React state management using Redux and well-designed Redux state structure from the redux state to the component level local state, implemented asynchronous actions using redux-thunk middleware, worked with dispatch for serial API calls, designed and developed the loading data conditions.

Consumed java web service to load rules data and post to save the rules and use D3.js to visualize data, managed necessary packages such as babel, webpack-dev-server, sass loader and react-hot-loader, Debugged frontend by Chrome Dev Tools, debugger, react and redux dev tool.

Frontend Developer Jan 2017 – Jan 2018

Best High Technologies LLC, Princeton, NJ

bTrade stock Trading platform, internal Timesheet record frontend development, and company web page development.

Used Angular to create a Single Page dashboard and provide stock real time data.

Created reusable business logic, transferred and shared data between different controllers and services.

Implemented table and Form control using JavaScript and Angular and integrated RESTful APIs with front end Pages by generating JSON data from MySQL Database.

Web Developer Innovatis Technologies LLC, Jersey City, NJ Jan 2016 – December 2016

Shopping Cart Web/UI development and deliver UI features including items list, form control, data order, and services.

Developed SPA Single Page Application using AngularJS and MVC pattern and angular custom Directives for DOM manipulation and code reuse.

Consumed RESTful web service, processed, transferred JSON items list data using Angular factory and service.

Electrical Engineer August 2011 – Dec 2013

China Guodian Corporation, Zhaoqing, China

Education

Online Master of Computer Science Harrisburg University of Science & Technology January 2019 - January 2021

Master of Electrical Engineering Stevens Institute of Technology January 2014 - December 2015

Bachelor of Electrical Engineering and Automation Guangdong University of Technology July 2007 - July 2011

Certifications

Java Data Structure & Algorithms – [Scott Barrett]

Next.js Ecommerce Platform – [Brad Traversy]

React Full Stack Development with Spring Boot – [Senol Atac]

Highlighted Projects

E-Commerce Platform: Developed complex UI with real-time data visualization using React and Chart.js, Built configurable multi step forms with performance optimization.

Finance Analytics App: Implemented complex state management and API integrations for real-time reporting and analytics tracking.

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